Pressure cooker



Aug. 28, 1928.

A. VISCHER, JR

PRESSURE COOKER Filed Sec. 29, 1921 Patented Aug. 28, 1928.

UNITED STATES ALFRED VISCHER. JR. OF FLORAL PARK, NEW YORK, ASSIGNOR TO SELF SEAL PRES- PATENT OFFICE.

SURE COOKER CO., INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

,PRESSURE COOKER.

Application filed December 29, 1921.

This invention relates to containers and with regard to certain more specific features, to pressure cookers.

Among the several objects of the invention may be noted the provision of a simple construction for sealing the container against escape of steam or water; and the provision of an inexpensive retainer or clamp between the .body and the cover of the container. Other is shown one of various possible embodiments of this invention,

Figure 1 is an elevation partly in section of a preferred form of container. I

Fig. 2 is a perspective of a spring ring, showing the ring expanded.

Fig. 3 is a similar View, showing the ring contracted, that is, in normal position with respect to the container; and,

Fig. 4 is a detail elevation of a handle.

Similar reference characters indicate corresponding parts throughout the several views of the drawings,

Referring now more particularly to Fig. 1, there is illustrated a container ha ing the side or body or main portion 5 of a suitable material, such as aluminum, and a lid or cover or closure 7 constructed preferably of steel. A valve 9 in the cover permits escape of fluid from the container whenever the pressure of said fluid exceeds a predeter-' mined amount, or at any time at the will of the operator. The lid terminates in an annular flange 11 which at normal or room temperatures has a sliding fit upon the upper outer edge of the flange 12 on the body 5, but which at supernormal temperatures is pressed tightly against said body owing to the fact that the lid is of amaterial having a lower temperature coeflicient of expansion than the bod A shoulder 13 on the flange 12 limits the downward or inward movement of the lid. A spring ring 15 is normally fitted around flanges 11 and 12 and tends to prevent the Serial No. 525.665.

cover from being removed from the bodv of the container. v

The valve 9 above mentioned comprises a tube 25 passing through and upwardly from the lid 7, and a weight 33 mounted on the tube. The weight tends to close the tube. The annular space 27 between tube and weight permits egress of fluid from the container when the pressure in the container forces the weight upwardly. The valve thus opens automatically to relieve the pressure within the container whenever such pressure exceeds a predetermined amount.

When the container is at temperatures above normal, the expansion of the body with respect to the lid causes the flange 11 of the lid to fit tightly against the outer surface of the body, to form therewith a pressure-tight oint. his makes it possible to dispense with the clamping devices commonly employed to Insure a pressure-tight joint, and in View of the fact that at normal temperatures this joint between lid and body is simply a sliding fit, it is possible for the operator to put the lid on and off at normal temperatures With ease.

The device may be operated as follows: Into the body 5 are placed suitable materials or ingredients. The cover is then slipped onto the body until the flange 11 of the cover abuts against the shoulder 13 on the body. The spring ring 15 is then held in expanded position (Fig. 2) by the fingers and inserted in place. When the spring ring 15 is in place. the lid may be pulled outwardly far enough to bring the flange 11 against the ring but this is not absolutely necessary, because the pressure within the container as soon as cooking gets under way, may cause this movement automatically, and if it does not do so, the device will ordinarily seal itself anyway. The container is now ready to be heated. This heating ordinarily causes the pressure within the container to rise above atmospheric pressure. This heating automatically causes the joint between flange 11 and cover 7 to be pressure-tight for the reasons above set out. The internal pressure within the container can be relieved at any time to any desired extent by grasping the wood knob 32 and lifting the weight 33. The point 36 that closes the opening in the upstanding tube is protected from extraneous dust and dirt. Excessive pressure is automatically relie d -by the lifting ofsaid weight and the resulting ening of the valve 9. When the lid is to e removed, the internal pressure may be partly or, entirely relieved by lifting the weight 33; the rim of thebody may be cooled by running cold'water 1n the trough 28 or in any other suitable way. The spring ring ma be compressed .with the fingers and remove after which the lid 7 maybe easily pulled away from the body portion. If a partial vacuum is formed within the container at any time, due to cooling of the container, such vacuum may be relieved manually by lifting the weight.

By virtue of the construction herein shown, the contactbetween body and container is along a surface 18 so narrow as tobe substantially only a line. This minimizing of the area of contact increases the pressure per square inch of contact for a given total pressure developed by the unequal expans1on of body and cover, and ensures a tight seal even at temperatures not far above normal or room,

temperature.

A pressure gauge 22 of suitable construction indicates the pressure within the container.

The pans 38 (if more than one ls'used) are preferably oval or of other non-circular form, and alternate pans are in staggered relatlon in order to space the pans and permit passage of steam and vapors from one to the other. Handles 40 may be riveted on -the ans.

The outstanding rim 24 protects the ring and adjacent parts from deformation by external blows; in addition to forming the trough 28 above mentioned.

Handles 21 are shown in Figs. 1 and 4.

The downwardly extending head 26 on the cover is spaced inwardly from the junction of cover and body and causes the condensed steam on the cover to drop off at the bead instead of reaching the junction of cover and bod Iii view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results at tained.

maaaos As various possible embodiments might be 'made of the above invention and as various expansion, the two parts being readily separable at normal or room temperatures, and

the closure fitting snugl the mouth of the body and being adapted to .form a sealing contact therewith by virtue of the unequal expansion coefiicient of body and closure when the parts are at super-normal temperatures,

a spring ring around the outside ofthe cover and-the body and holding the cover against removal from the body; and an annular basin formed near said mouth adapted to receive water for cooling the body.

2. A container combining a body and a closure, and means tending to retain thelatter in position on the former, the body and closurev having unequal thermal coeflicients ofexpansion, the two parts being readily separable at normal or room temperatures but said parts being so arranged as to form,

by virtue of said unequal coeflicients, a

substantially line sealing contact with one another at super-normal temperatures; the cover having a downwardly extending bead spaced inwardly from the junction of body and cover and adapted to prevent condensed steam on the inner side of the cover from reaching the'junction of body and cover.

3. A container combining a body and closure and elongated non-circular superposed pans arranged in staggered relation to space the pans and permit passage of steam and vapors from one pan to the other.

In testimony whereof, I have signed my name to this specification this 28th day of December, 1921.

ALFRED VISCHER, J R. 

